Vehicle engine multi-stage limiting speed governor

ABSTRACT

A vehicle engine multi-staged limiting speed governor for use on an existing engine governor having a governor casing and a speed control compression spring. The multi-stage limiting speed governor comprises an elongated housing having one end closed and secured at the opposite end thereof to the existing governor casing, a longitudinally extending plunger centrally disposed within the housing having one end thereof extending into the existing governor casing for depression of the existing speed control compression spring, a plurality of spaced pistons slidably disposed within the housing between the plunger and the closed end of the housing, a plurality of piston stopping means for independently limiting the travel of each piston in either longitudinal direction, a separate air inlet port provided in the housing for each piston to induce travel of said piston toward the plunger, switching means for selectively directing air into the desired inlet port, and interacting piston rods for transferring the motion of one piston to the adjacent piston whereby upon directing air to a selected piston that piston will travel toward the existing governor casing imparting travel to each successive piston and in turn depressing the plunger against the speed control spring until the acting piston reaches a piston stop, thereby limiting the engine to a speed corresponding to the longitudinal displacement of the plunger.

United States Patent [19] Mitchell VEHICLE ENGINE MULTI-STAGE LIMITING SPEED GOVERNOR [75] Inventor: Guy E. Mitchell, Tulsa, Okla. [73] Assignee: McMichael Construction Co., Tulsa,

Okla.

[22] Filed: Jan. 7, 1972 {21] Appl. No.: 216,205

[52] US. Cl. 91/178, 92/l3.l, 92/63, 92/84 [51] Int. Cl. F0lb 7/00 [58] Field 01 Search 92/63, 84, 13.1, 13.6; 91/ 167 [56] References Cited UNITED STATES PATENTS 2,456,712 12/1948 Kremiller 92/84 2,761,473 9/1956 Denton 91/167 3,213,886 10/1965 Pearne 92/13.l 2,415,783 2/1947 Bassett et al.. 92/63 2,533,627 12/1950 Roach 92/63 2,757,640 8/1956 White 92/63 3,090,359 5/1963 Hoppenstand.... 92/63 3,143,143 8/1964 Taylor et a1. 92/63 3,159,375 12/1964 Schrecongost et a1 92/63 FOREIGN PATENTS OR APPLICATIONS 308,493 11/1936 France 92/84 Apr. 23, 1974 Primary Examiner-Paul E. Maslousky v Attorney, Agent, or FirmWilliam S. Dorman 5 7] ABSTRACT A vehicle engine multi-staged limiting speed governor for use on an existing engine governor having a governor casing and a speed control compression spring. The multi-stage limiting speed governor comprises an elongated housing having one end closed and secured at the opposite end thereof to the existing governor casing, a longitudinally extending plunger centrally disposed within the housing having one end thereof extending into the existing governor casing for depression of the existing speed control compression spring, a plurality of spaced pistons slidably disposed within the housing between the plunger and the closed end of the housing, a plurality of piston stopping means for independently limiting the travel of each piston in either longitudinal direction, a separate air inlet port provided in the housing for each piston to induce travel of said piston toward the plunger, switching means for selectively directing air into the desired inlet port, and interacting piston rods for transferring the motion of one piston to the adjacent piston whereby upon directing air to a selected piston that piston will travel toward the existing governor casing imparting travel to each successive piston and in turn depressing the plunger against the speed control spring until the acting piston reaches a piston stop, thereby limiting the engine to a speed corresponding to the longitudinal displacement of the plunger.

4 Claims, 3 Drawing Figures APR 23 1974 SHEET 1 OF 3 1 WV/ I NM m QATENTEUAPR 23 19% 33305 6 SHEET 3 OF 3 a Www x @SM an mm 2 km 8 E QMKQQQ vi No N BACKGROUND OF INVENTION This invention relates to a multi-stage limiting speed governor for use with existing engine governors and more particularly, but not by way of limitation, to a multi-staged limiting speed governor for installation on the usual engine governor provided onexisting diesel engines and includes elements added to the existing governor which do not hinder the normal operation thereof, but merely add additional speed limitations on the engine upon command by the operator of the vehicle.

In the mixing of concrete, in the normal diesel engine concrete hauling trucks, it is very important to control the speed of rotation of the mixer during the charging period and the initial mixing period. The rotation of the mixer is accomplished by the engine of the vehicle upon which the mixer is mounted. The usual vehicle driver is often very careless in the control of the mixer and frequently may set the vehicle engine wide open and leave the immediate site of the running engine duringthe charging and mixing period. This results in a bad mixture for the resulting concrete. Even if the operator of the vehicle is attentive, to control the various speeds of the mixer would require that the vehicle be equipped with a tachometer and the operator would be required to sit and monitor that tachometer attempting to keep the vehicle engine running at the appropriate speed.

SUMMARY OF INVENTION The present invention contemplates a novel multi-.

staged limiting speed governor whichattaches to the existing engine governor and provides a plurality of stages between the idle speed of the engine and the high speed operation of the engine. This attaching governor will not hinder the normal operation of the vehicle engine, but will merely addthese intermediate engine speed stages upon comm-and by the operator. This limiting speed governor attachment is provided with a plurality of air actuated pistons which serve to depress the existing governor high speed compression spring to various levels corresponding to the engine speed that is desired.

The use of this invention will provide the vehicle operator with more freedom of movement around the site allowing him to monitor the complete charging and mixing operation and, at the same time, providing the best possible mixture of the resulting concrete.

Other and further advantageous features of the present invention will hereinafter more fully appear in connection with a detailed description of the drawings in which:

DESCRIPTION OF DRAWINGS FIG. I is a sectional elevational view of a three stage limiting speed governor embodying the invention in which the governor is attached to the usual governor provided on a Detroit diesel engine.

FIG. 2 is a sectional elevational view of a two-stage limiting speed governor embodying the invention.

FIG. 3 is a sectionalelevational view of a four stage limiting speed governor embodying the invention.

DETAILED DESCRIPTION Referring to the drawings in detail, reference character 10 generally indicates a three-stage limiting speed governor attached to the usual engine speed governor 12 of a Detroit diesel engine. The existing governor is provided with an outer casing 14 for housing the usual engine governor mechanism. The existing governor 12 on a diesel engine is normally provided with two speed controls, one for idle, and one for high speed operation. The speed control is effected by the centrifugal force of revolving governor weights (not shown). This centrifugal force is converted into linear motion which is transmitted to an operating shaft also not shown which bears against the governor compression springs, one for idle and one for high speed. lnthe idle speed range, the centrifugal force of the low speed weights and the high speed weights (not shown) operate against the low speed spring, also not shown. As the engine speed increases, the centrifugal force of both pairs of weights compresses the low speed spring until the low speed weights have reached the limit of their travel, at which time the low speed spring is fully compressed.

As the engine speed continues to increase, the.centrifugal force of the high speed weights increases until this force overcomes the high speed spring and the governor again takes control of the engine, limiting the maximum speed of the engine.

The high speed control of the existing engine governor comprises anelongated plunger16 which extends into the engine governor casing, it is provided at one end thereof with a spring cap retainer l8,'the other end of said high speed plunger extending out of the casing 14 through a port 20 provided in the casing. An elongated helical high speed compression spring 22 is disposed around the high speed plunger 16 having one end thereof retained by the spring cap retainer 18. The opposite end of said high speed compression spring 22 being retained by a spring retainer washer 24. The outer limit of travel of the high speed compression spring 22 is limited by an adjustable spring retainer 26. The spring retainer 26 comprises a cylindrical threaded spring retaining nut which is threadedly disposed within the governor casing 14 through the port 20 of said governor casing. The spring retainer 26 is further provided with an interior annular shoulder 28 which serves to stop the outer travel of the compression spring 22 when the spring retainer washer 24 butts against the shoulder 28. The desired high speed engine level setting is accomplished by threadedly adjusting the depth of the spring retainer 26 in and out of the governor casing 14. When the desired high speed engine level is set, a lock nut 29, which is threadedly disposed about the spring retainer 26, is tightened against the governor casing 14 thereby holding the spring retainer 26 at this desired position.

The three stage limiting speed governor 10 comprises an elongated cylindrical housing 30 having one end thereof secured to the existing governor casing 14 by a plurality of threaded bolts 32 which extend longitudinally through the walls of the housing 30, said bolts being threaded into the governor casing 14. The outer end of the housing 30 is closed by a cap plate 34 which is secured to the outer end of said housing 30 and is sealed by a suitable gasket 36 interposed between the housing 30 and the cap plate 34.

A longitudinally extending plunger sleeve 38 is centrally disposed within the housing and having one end thereof extending into the spring retainer 26 and slidably disposed about the high speed plunger 16 of the existing governor 12. The end of the plunger 38 is butted against the spring retainer washer 24 whereby upon depression of the plunger 38 toward the governor casing 14, the compression spring 22 is depressed within the spring retainer 26. The opposite end of the plunger 38 is provided with a cap plate 40, said cap plate having an annular flange 42 extending outwardly from the cap plate for a purpose that will be hereinafter set forth.

A first cylindrical piston 44 is slidably disposed within the housing 30, the plunger side of said piston being provided with a bore 46 extending into the piston 44 for accepting the cap plate 40 of the plunger 38 therein. The piston 44 is also provided with a bore 48 which extends part way into the piston and is conterminous with the bore 46 resulting in an annular shoulder 50 for acceptingthe flange 42 of the plunger cap 40 thereon. The outer periphery of the piston 44 is provided with an annular groove 52 for accepting an O- ring seal 54 therein.

The opposite end of the piston 44 is provided with an annular recess 56 about the outer portion thereof. When the piston 44 is forced against the plunger 38 as will be hereinafter set forth, thetravel of the said piston 44 toward the existing governor 12 will be limited by the piston coming to rest against the spring retainer 26. Travel of the piston44 in the opposite direction away from the existing governor 12 is limited by a circular separation plate 58 which is rigidly disposed within the housing 30, said separationplate having a centrally disposed bore 60 provided therein.

A second substantially identical piston 62 is slidably disposed within the housing 30 between the separation plate 58 and the outer end cap 34. Likewise, one end of the piston 62 is provided with a centrally disposed bore 64 and associated conterminous bore 66 similar to the bores 46 and 48 of the first mentioned piston for purposes of interchangeability therewith. The piston 62 is also provided within an annular groove 68 around the outer periphery/thereof for accepting a suitable O- ring seal 70 therein. The opposite end of the piston 62 is provided with an annular recess 72 around the outer periphery thereof. The piston 62 is provided with a centrally disposed bore 74 and a longitudinally extending piston actuating rod 76 threadedly disposed therein. The longitudinal position of the actuating rod 76 may be adjusted, for purposes that will be hereinafter set forth, by threadedly passing the rod within the piston bore 74. When the desired position of the rod 76 is reached, that position is secured by a suitable lock nut 78 being tightened against the piston 62. An adjustable limiting screw 80 is threadedly disposed and centrally located through the end cap plate 34 and extends longitudinally into the housing for limiting the outer travel of the piston 62. The travel of the piston 62 toward the existing governor 12 is limited by the piston 62 coming to rest' against the separation plate 58. The limiting screw 80 is provided with a lock nut 82 which may be secured against the end cap 34 when the limiting screw 80 has been adjusted to the proper depth. When the piston 62 is forced to travel toward the existing governor 12 in a manner that will be hereinafter set forth, the piston actuating rod 76 will come in contact with the piston 44 and induce travel of the piston 44 toward the existing governor 12. The piston 44 will in turn depress the plunger 38 thereby compressing the high speed compression spring 22. A first air inlet port 84 is provided through the housing 30 adjacent to the separation plate 58 and located on the governor side of said separation plate 58. Therefore, when compressed air is introduced into the piston chamber through the inlet 84, the piston 62 will be forced back against the limiting screw and the piston 44 will be forced to travel the existing governor 12, at the same time depressing the plunger 38 which, in turn, will cause compression of the high speed compression spring 22. As hereinbefore set forth, the piston 44 will travel until it reaches and comes into contact with the spring retainer 26.

A second air inlet port 86 is provided in the housing 30 adjacent to the end plate 34. When compressed air is removedfrom the port 84 and is applied through the port 86 into the piston chamber, the piston 62 will be forced to travel toward the existing governor 12. As hereinbefore set forth, the piston actuating rod 76 will engage the piston 44 which will in turn depress the plunger 38 thereby compressing the compression spring 22. The piston 62 will continue this travel until it reaches the separation plate 58. It should be noted that when applying air to the inlet port 84 to activate the piston 44, it is not necessary that the air be removed from the port 86.

I in operation when the vehicle carrying .the concrete mixer is'parked at the loading area wherein the concrete mixer is being charged with the concrete mixture, it is desirable to limit the revolutions of the mixer to approximately l2 r.p.m. to provide the best end result. This 12 r.p.m. mixer speed is obtained by suitable gearing (not shown) of the mixer drum with the engine of the vehicle. During the period in which the concrete mixer is being charged there is no compressed air being supplied to either the inlet port 84 or 86 and the plunger 38 therefore, is fully extended and the spring retainer washer 24 will be butted against the shoulder 28 of the spring retainer 26. When the full charge of concrete mixture has been loaded into the mixer,-it is desired to limit the mixing speed to approximately l4 r.p.m. This 14 r.p.m. mixer speed is'obtained by introducing compressed air through the inlet port .86 into the piston chamber, thereby forcing the piston 62 against the separation plate 58 which in turn, through action of the piston actuating rod 76, forces the piston 44 against the plunger 38. The depression of the plunger 38 compresses the high speed compression spring 22 to a new level which increases the r.p.m. of the engine so that through the same gearing mentioned hereinbefore, the concrete mixer obtains a rotating,

speed of 14 r.p.m. When the mixing cycle is completed, the operator may switch the compressed air from the inlet port 86 to the inlet port 84 thereby forcing the piston 44 further toward the existing governor 12 thereby depressing the plunger 38 which in turn compresses the high speed compression spring 22. The piston 44 will continue its travel until it comes to rest against the spring retainer 26. This allows the vehicle engine to operate at its maximum r.p.m. for highway operation. However, at this point it is desirable to lower the rotation of the mixer drum to approximately 2V2 r.p.m. This is accomplished by a suitable gear (not shown) that is engaged by the vehicle operator to reduce the rotating speed of the mixing drum to approximately 2% r.p.m.

when the vehicle engine is operating at maximum speed. It is noted that the high rpm. speed of the vehicle engine may be adjusted by interposing a plurality of spacing shims 85 of a desired thickness between the plunger cap 40 and the piston 44.

As hereinbefore set forth, the present invention is not limited to a three stage governor as described in detail, but may consist of as many stages as necessary by simply increasing the number of spaced pistons in the housing 30. It is also apparent that the present invention may be configured as a two stage limiting speed governor as generally indicated in FIG. 2 by reference character 87. In this two stage configuration only the piston 44 is slidably disposed within the housing 30 and again is limited in its direction of travel towards the existing governor 12 by coming to rest against the spring retainer 26. The travel of the piston 44 in the opposite direction away from the existing governor 12 is limited by the adjustable limiting screw 80. Only one air inlet port 86 is provided through the housing 30 to drive the piston 44 toward the existing governor 12.

A switching means 88 is provided to direct compressed air to the ports 84 or 86. The inlet port 90 of the switch 88 is connected to the usual vehicle compressed air supply (not shown). The outlet port 92 is connected to the port 84 by a suitable hose 94 and the outlet port 96 is connected to the port 86 by a suitable hose 98. in the two-stage governor 87 a similar switch 100 is provided having only one outlet port 102 for connection with the port 86 by a suitable hose 104.

As shown in FIG. 3, reference'character generally indicates a four stage limiting speed governor attached to the usual speed governor 12 of a Detroit diesel engine. FIG. 3 shows substantially what has been described previously with respect to FIG. 1, except that the cylindrical housing has been somewhat elongated to provide an intermediate piston 62 between the left-hand end piston 62 and the right-hand end piston 44. The intermediate piston 62 is identical to the lefthand piston 62 previously described in relation to FIG. 1. The previously described separation plate 58 with the central bore 60 is now interposed between the two identical pistons 62 and an additional identical circular separation plate 58 with a centrally disposed bore60 is interposed between the central piston 62 and the righthand piston 44. The first air inlet port 84 is disposed to the right of the separation plate 58 between the two identical pistons 62 and the second air inlet port 86 is at the end of the housing 30 as previously described. The ports 84 and 86 are connected to the switching means 88 by means of the hoses 94 and 96 previously described and the switch 88 is provided with an inlet port 90 as previously described. immediately to the right of the separation plate 58 which is between the central piston 62 and the right-hand piston 44 is a third inlet port 84 which is connected to the switching means 88 by means of the hose 94'. The operation of the embodiment shown in FIG. 3 will be obvious when considered in light of the description of the operation of the embodiment of FIG. 1 above.

From the foregoing, it is apparent that the present in vention provides a vehicle engine multi-stage limiting speed governor for use with an existing engine governor which does not hinder the normal operation of the existing governor, but provides additional stages of speed control for the vehicle engine. This novel multistage limiting speed governor is economical and dura- What is claimed is:

1. In combination with an existing engine governor having a governor casing, speed control compression spring means, associated spring retainer, and high speed plunger, a multi-stage limiting speed governor comprising an elongated housing having one closed end and being secured at the opposite end thereof to the existing governor casing; a longitudinally extending elongated cylindrical sleeve member centrally disposed within the housing and slidably disposed within the existing spring retainer and about the existing high speed plunger, the end of said sleeve being in engagement with the speed control compression spring means and the opposite end of said sleeve having a cap secured thereto; a plurality of spaced pistons slidably disposed within the housing between the sleeve and the closed end of the housing; a plurality of piston stopping means for independently limiting travel of each piston in either longitudinal direction; a separate air inlet port provided in the housing for each piston to induce travel of said piston toward the plunger; switching means for selectively directing air into the desired inlet port; and at least one interacting piston rod for transferring the motion of one selected piston to the adjacent piston; whereby, upon directing air to said one selected piston that piston will travel toward the existing governor casing imparting travel to each successive piston and in turn depressing the sleeve against the speed control compression spring until the selected piston reaches a piston stop.

2. The improvement as set out in claim l wherein a first piston of said plurality of pistons is adjacent to the cap of the sleeve and is cylindrical in cross-sectional shape and slidably disposed within the housing withthe outer periphery of said piston being provided with an annular groove and an O-ring seal being disposed within said annular groove for providing an air tight seal on either side of the piston and wherein each successive piston is substantially identical in shape to the first piston and having in addition thereto an elongated piston actuating rod longitudinally and centrally disposed therethrough.

3. The improvement as set out in claim 2 wherein the piston stopping means comprises the existing governor spring retainer for limiting travel of the first piston toward the existing governor casing, a circular separation plate disposed within the housing on the opposite side of the first piston and having a centrally disposed bore therethrough, said separation plate limiting the travel of the first piston in the opposite direction and also serving to limit the travel of the second successive piston in a direction toward the existing governor casing, a plurality of spaced separation plates substantially identical to the first separation plate being interposed between each successive pair of pistons and rigidly secured to the interior of the housing, and an elongated adjustable limiting screw longitudinally and centrally disposed within the outer closed end of the housing for 8 each successive piston is likewise located adjacent to that pistons associated separation plate and wherein the last air inlet port for the last successive piston is located adjacent to the closed end of the housing 

1. In combination with an existing engine governor having a governor casing, speed control compression spring means, associated spring retainer, and high speed plunger, a multi-stage limiting speed governor comprising an elongated housing having one closed end and being secured at the opposite end thereof to the existing governor casing; a longitudinally extending elongated cylindrical sleeve member centrally disposed within the housing and slidably disposed within the existing spring retainer and about the existing high speed plunger, the end of said sleeve being in engagement with the speed control compression spring means and the opposite end of said sleeve having a cap secured thereto; a plurality of spaced pistons slidably disposed within the housing between the sleeve and the closed end of the housing; a plurality of piston stopping means for independently limiting travel of each piston in either longitudinal direction; a separate air inlet port provided in the housing for each piston to induce travel of said piston toward the plunger; switching means for selectively directing air into the desired inlet port; and at least one interacting piston rod for transferring the motion of one selected piston to the adjacent piston; whereby, upon directing air to said one selected piston that piston will travel toward the existing governor casing imparting travel to each successive piston and in turn depressing the sleeve against the speed control compression spring until the selected piston reaches a piston stop.
 2. The improvement as set out in claim 1 wherein a first piston of said plurality of pistons is adjacent to the cap of the sleeve and is cylindrical in cross-sectional shape and slidably disposed within the housing with the outer periphery of said piston being provided with an annular groove and an O-ring seal being disposed within said annular groove for providing an air tight seal on either side of the piston and wherein each successive piston is substantially identical in shape to the first piston and having in addition thereto an elongated piston actuating rod longitudinally and centrally disposed therethrough.
 3. The improvement as set out in claim 2 wherein the piston stopping means comprises the existing governor spring retainer for limiting travel of the first piston toward the existing governor casing, a circular separation plate disposed within the housing on the opposite side of the first piston and having a centrally disposed bore therethrough, said separation plate limiting the travel of the first piston in the opposite direction and also serving to limit the travel of the second successive piston in a direction toward the existing governor casing, a plurality of spaced separation plates substantially identical to the first separation plate being interposed between each successive pair of pistons and rigidly secured to the interior of the housing, and an elongated adjustable limiting screw longitudinally and centrally disposed within the outer closed end of the housing for limiting the travel of the last piston in a direction away from the existing governor casing.
 4. The improvement as set out in claim 3 wherein the air inlet port for the first piston is located adjacent to the first separation plate on the piston side of the said separation plate and each successive air inlet port for each successive piston is likewise located adjacent to that piston''s associated separation plate and wherein the last air inlet port for the last successive piston is located adjacent to the closed end of the housing. 